Plastic closure flange assembly



April 8, 1969 H. R. HELWIG PLASTIC CLOSURE FLANGE ASSEMBLY Filed Aug. 22, 1967 INVENTOR. HA4 s51 R H54 w/a ATTORNE};

United States Patent 3,437,226 PLASTIC CLOSURE FLANGE ASSEMBLY Halsey R. Helwig, Clifton, N.J., assignor to American Flange & Mfg. Co. Inc, New York, N.Y., a corporation of Delaware Filed Aug. 22, 1967, Ser. No. 662,532 Int. Cl. B65d 41/04 US. Cl. 220-39 11 Claims ABSTRACT OF THE DISCLOSURE A plastic closure flange which is secured to an upstanding container wall opening formation by means of a metal sealing ring. The flange is internally threaded and provided with an improved integral gasketing portion. A self gasketing plastic plug is threadedly engaged within the flange so as to effectively seal against the flange gasketing portion.

This invention relates to plastic closures for containers and is particularly concerned with a closure flange and plug assembly embodying an improved sealing relationship therebetween.

The now widespread practice of shipping and storing chemically corrosive fluids in drums suitably lined or otherwise protected against corrosion has created a demand for more effective closures for use on such drums. Although there have been some previous attempts to satisfy this demand these constructions have more than anything else only emphasized the problems involved in effectively sealing drums with closure elements constructed primarily of corrosive resistant materials. One of these constructions embodies an internally threaded closure flange formed of synthetic plastic material and provided with a peripheral sealing lip which is secured to an upstanding container opening formation by means of a metal securing ring. The closure is completed with the threaded engagement of a synthetic plastic plug within the flange. One of the prior art drawbacks in this construction resides in the fact that the rotational torque required to seal the plug in the flange is frequently only slightly greater in magnitude than the torque value sufficient to cause the interengaged threads to strip or jump over each other. Also inherent in this particular type of closure construction are three separate possible leakage paths. One exists between the flange sealing lip and the surrounding container opening formation. Another exists between the flange and the plug threadedly engaged therewith. A third possible leakage path exists in some constructions between the flange sealing lip and the overlying metal securing ring.

The plastic flange and plug assembly herein disclosed takes into account all three of the above mentioned leakage path possibilities and provides improved safeguards against each. In addition the closure assembly of the invention possesses structural qualities heretofore thought unattainable in a plastic construction. One of these qualities being characterized by the wide differential between the relatively low sealing torque and the relatively high stripping torque. These improved features are all embodied in a low cost closure fitting utilizing a minimum amount of material and employing unique relationships to effect maximum sealing performance.

It is accordingly a principal object of the invention to provide new and improved plastic closures for containers.

Another object is to provide an improved plug, flange and container wall closure construction.

A further object is to provide a new sealin g relationship between a plastic flange and a self gasketing plastic plug.

Further atnd more detailed objects will in part be obvious and in part pointed out as the description of the 3,437,226 Patented Apr. 8, 1969 invention taken in conjunction with the accompanying drawing proceeds.

In that drawing:

FIG. 1 is a part sectional part elevational view of the closure flange assembly formed in accordance with the invention;

FIGURE 2 is an elevational view of the closure plug of the invention;

FIG. 3 is a top plan view of the flange and plug assembly;

FIG. 4 is a fragmentary sectional view of the sealing portion of the flange assembly;

FIG. 5 is a fragmentary sectional view similar to FIG. 4 and also showing the plug and a container wall section; and

FIG. 6 is a part sectional part elevational view of the complete closure assembly secured within a container Wall opening and with the flange diaphragm removed.

The flange assembly 1 of the invention as seen in FIG. 1 comprises a plug receiving flange member molded of synthetic plastic material generally indicated at 2 and having a downwardly extending wall 3 internally threaded at 4 and terminating at its lower end in a radially inwardly extending annular ledge 5 integrally connected through a weakened tearing section 6 to a hand removable diaphragm 7. Integrally connected to the diaphragm 7 is a pull member to facilitate hand removability of the diaphragm comprising a neck 8 extending upwardly and radially inwardly from the diaphragm closely adjacent the weakened tearing section 6 and terminating in ring 9 adapted to receive a persons finger. As clearly seen in FIG. 1 the diaphragm 7 is formed with a pocket 10 for reception and storage of the pull member when a plug is screw into the flange. The threaded wall 3 has an uppermost end portion 11 from which extends a peripheral sealing lip having a radially outwardly extending top wall 12 and a downwardly extending outer wall 13 which terminates in a lowermost end 14.

In FIG. 4 it can be seen that an annular downwardly extending groove is formed in the top of the threaded wall 3 having an outer surface 15, a bottom surface 16 and an inner surface 17. The resulting wall 18 spaced radially inwardly of the upper end portion 11 terminates at its upper end in a downwardly and radially inwardly inclined surface 19 and carries at least a portion of a full thread around its inner surface as indicated at 4a.

The plug receiving member 2 thus described is assembled with a metal securing ring 20 having an inner leg 21, a top portion 22 and an outer leg 23. The metal securing ring 20 is assembled to the plug receiving member 2 in overlying engagement with the peripheral sealing lip so that the leg 21 extends into the flange groove and tightly engages the groove outer surface 15. In the assembled construction as seen in FIG. 4 there exists a slight gap between the leg 21 and the groove inner wall 17 and also between the lower end of the leg 21 and the groove bottom 16. This clearance aids the assembly operation and assures a close fit around the entire outer surface of the flange sealing lip.

FIGS. 2 and 3 illustrate a closure plug 30 also molded of synthetic plastic material for threaded engagement within the flange member 2 comprising a cylindrical sidewall 31 having a screw thread 32 thereon and having an enlarged annular head 33 extending radially outwardly of said sidewall 31 above the thread 32. In FIG. 5 the plug head 33 is shown in detail as having a lower surface 34, an upwardly and outwardly inclined surface 35 and an upwardly and inwardly radiused top surface 36. The top surface of the plug 30 has a plurality of wrench or finger engaging recesses 37 and 38. In the center of the plug there is formed a downwardly extending internally threaded neck 39 terminating at its lower end in an integral cut out diaphragm 40. The plug 30 is thus designed to be used as shown or to receive either a plug or a faucet within the neck 39.

The plug receiving flange assembly with or without the plug 30 engaged therewith is secured to a filled container having a suitably formed opening to receive the same. FIG. 5 shows a container wall 50 with an upstanding opening formation comprising an upwardly extending portion 51, an uppermost outwardly curled portion 52 and a downwardly and radially inwardly extending portion 53 which terminates in a free edge 54. The flange assembly 1 is permanently secured to the above described opening formation by placing the flange sealing lip thereover and forming the securing ring leg 23 radially inwardly adjacent its lower edge so as to pinch the lowermost end 14 of the lip outer wall 13 against the free edge 54 and cause the plastic material to be squeezed therebetween as shown. This squeezing out of the plastic material between the two adjacent free metal edges has been found to assure a tight leakproof joint between the flange assembly and the container wall regardless of the abuse the closure may be subjected to.

Of importance is the sealing relationship thus achieved between the plug and the flange assembly after the diaphragm has been torn out to gain initial access to the container. In FIGS. 5 and 6 it can be seen that upon screwing the plug 30 into the plug receiving member 2 the inclined surface 35 on the plug head 33 eventually engages the inclined surface 19 on the plug receiving member wall 18. These surfaces 35 and 19 are both inclined at approximately a 45 degree angle so that once initial contact therebetween is made very little additional turning torque is required to cause the wall 18 to be urged radially outwardly. A gasketing action is immediately aflected and constantly improves as continued rotation of the plug causes the groove inner surface 17 to contact the securing ring leg 21 closing up the gap therebetween illustrated in FIG. 4. At this point the torque value required to effect further turning of the plug increases greatly due to the rigidity of the wall 18 now directly backed up by the leg 21 of the metal securing ring 20. Moreover the support given the top thread portion 4a by the securing ring makes it very diflicult for the plug threads 32 to jump over the threads 4 on the flange member resulting in an unusually high stripping torque. This large differential between the minimum etfective sealing torque and the stripping torque distinguishes the invention from the prior art. Also of importance in the disclosed construction is not only the effective closing off of any possible leakage path between the plug 30 and the plug receiving member 2 by the gasketing action of the inclined surfaces 35 and 19 but in addition the possibility of leakage between the ring 20 and the plug receiving member 2 is eliminated distinguishing over those constructions wherein the plug seals directly on the metal ring.

Having described my invention what I claim is new and desire to secure by Letters Patent is:

1. In closure construction, an annular plug receiving flange member molded of synthetic plastic material, said flange member defining an internally threaded axial dispensing passage, first gasketing surface means adjacent the upper end of said dispensing passage, an integrally molded sealing lip surrounding said member, an annular metal securing ring assembled to said plug receiving flange member in overlying relationship with said sealing lip, a closure plug molded of synthetic plastic material threadedly engaged within said dispensing passage, said plug including an integrally molded second gasketing means in sealing engagement with said first gasketing means and a portion of said plug receiving flange member interposed in a horizontal plane extending between said engagement of said first and second gasketing means and said securing ring.

2. In closure construction as in claim 1, said sealing lip extending radially outwardly at the uppermost end of said dispensing passage and then extending downwardly and terminating in a lowermost free end portion.

3. In closure construction as in claim 2, and metal securing ring having an inverted channel shaped crosssectional configuration comprising an inner leg, a top portion and an outer leg.

4. In closure construction as in claim 3, wherein said interposed portion of said flange member is in contact with said securing ring inner leg.

5. In closure construction as in claim 3, said sealing lip being sealingly engaged between said metal securing ring and an upstanding outwardly curled opening neck formation and said lowermost free end portion of said sealing lip extending free of said ring outer leg and said outward curl.

6. In closure construction as in claim 3, wherein part of said plug receiving flange member thread lies in a horizontal plane passing through said inner leg of said ring.

7. In closure construction as in claim 1, said first gasketing means comprising a radially outwardy and up wardly inclined annular surface.

8. In closure construction as in claim 7, said second gasketing means comprising an upwardly and outwardly inclined surface substantially parallel to said first gasketing means.

9. In closure construction as in claim 1, an upwardly opening annular groove formed in said flange member adjacent the upper end of said dispensing passage, said interposed flange member portion carrying said first gas keting surface means and forming the radially inner wall of said groove.

'10. In closure construction as in claim 9, said securing ring having a wall portion extending into said groove and below said first gasketing surface means.

11. In closure construction as in claim 10, wherein said thread formed along said dispensing passage extends to a point spaced above the bottom of said groove.

References Cited UNITED STATES PATENTS 2,772,017 11/1956 Rieke 22039 JAMES B. MARBERT, Primary Examiner. 

